1. Field of the Invention
The present invention relates to diamond wire saw devices and, more particularly, to diamond wire saw devices having a continuous diamond wire driven by a plurality of drive wheels, each with its own hydraulic motor, and suitable for all cutting applications, including underwater applications.
2. Technical Background
Diamond wire saws are known to be useful for cutting structures made of metal, cement, and plastics. U.S. Pat. No. 5,193,518 discloses a portable wire saw for cutting materials such as stone, concrete, and asphalt. The saw uses a continuous diamond wire driven by a single drive wheel powered by a hydraulic motor. U.S. Pat. No. 5,964,210 discloses a continuous diamond wire saw which also uses a tension pulley with a spring, and a lead screw to move the work piece to be cut by the saw. This type of saw is useful only with small objects such as silicon ingots. This saw does not provide a means of adjusting a tension pulley without a spring, and does not provide a lead screw that positions the saw instead of the work piece. U.S. Pat. No. 6,881,131 discloses a continuous diamond wire saw useful for cutting large metal structures in which tension in the wire saw is adjusted by making adjustments in the several support structures that hold the wire saw.
Cutting an object with a wire saw requires that the saw be held fixed and the work piece be moved through the wire saw, or that the work piece be held fixed and the wire saw be moved through the work piece. During the cutting process the tension in the wire saw can gradually decrease, and the distribution of tension around the wire can become non-uniform. Both decreased tension and non-uniform tension can lead to breaking of the wire saw. When cutting large objects underwater it is very difficult to maintain a fixed relationship between the underwater work piece and the wire saw, and to maintain a constant and uniform tension in the wire saw. Prior art diamond wire saws are unsatisfactory for this purpose. What is needed is a continuous diamond wire saw system and method that provides a practical means for maintaining a fixed relationship between the underwater work piece and the wire saw, and a constant and uniform tension in the wire saw.